#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>

int Drink(int empty)
{
	if (empty > 1)
	{
		int a = empty / 2;
		int b = empty % 2;
		return a + Drink(a + b);
	}
	else
	{
		return 0;
	}
}

int main()
{
	int i = 0;
	int money = 20;
	int ret = Drink(money);
	printf("%d\n", money + ret);
	return 0;
}
